Unable to wake Librem15 from suspend or hibernate

Sorry for the n00b question - but whenever I put my machine to “Suspend” or “Hibernate” I cannot seem to find a key combination to “awaken” it.

Ultimately, I have to hold the reset key to power it down and then re-boot.

Running Debian Mint - all the latest updates/upgrades daily.

Is there a key-combo for various Linux distro’s that will awaken these machines? Have had similar difficulty with different distro’s on this laptop (ubuntu, Linux Mint).

Thanks in advance,